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use crate::{DbBackend, Statement};
use sea_query::QueryStatementBuilder;
/// A Trait for any type performing queries on a Model or ActiveModel
pub trait QueryTrait {
/// Constrain the QueryStatement to [QueryStatementBuilder] trait
type QueryStatement: QueryStatementBuilder;
/// Get a mutable ref to the query builder
fn query(&mut self) -> &mut Self::QueryStatement;
/// Get an immutable ref to the query builder
fn as_query(&self) -> &Self::QueryStatement;
/// Take ownership of the query builder
fn into_query(self) -> Self::QueryStatement;
/// Build the query as [`Statement`]
fn build(&self, db_backend: DbBackend) -> Statement {
let query_builder = db_backend.get_query_builder();
Statement::from_string_values_tuple(
db_backend,
self.as_query().build_any(query_builder.as_ref()),
)
}
/// Apply an operation on the [QueryTrait::QueryStatement] if the given `Option<T>` is `Some(_)`
///
/// # Example
///
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .apply_if(Some(3), |mut query, v| {
/// query.filter(cake::Column::Id.eq(v))
/// })
/// .apply_if(Some(100), QuerySelect::limit)
/// .apply_if(None, QuerySelect::offset::<Option<u64>>) // no-op
/// .build(DbBackend::Postgres)
/// .to_string(),
/// r#"SELECT "cake"."id", "cake"."name" FROM "cake" WHERE "cake"."id" = 3 LIMIT 100"#
/// );
/// ```
fn apply_if<T, F>(self, val: Option<T>, if_some: F) -> Self
where
Self: Sized,
F: FnOnce(Self, T) -> Self,
{
if let Some(val) = val {
if_some(self, val)
} else {
self
}
}
}